Fully automatic cylindrical grinding machine



1941- H. A. SELVEN ETAL 2,229,312

FULLY AUTOMA'ITIC CYLINDRICAL GRINDING MACHINE Original Filed June 1, 1959 s Sheets-Sheet 1 amt/Micro HEHBERTFlSILVEN DUNHLDWSTEPHENEUN Z93 Zil wmwg W Jan. 21, 1941. H. A. SILVEN EI'AL 2,229,312

FULLY AUTOMATIC CYLINDRICAL GRINDING MACHINE Original Filed June 1, 1939 5 Sheets-Sheet 2 250 jwumikn- HERBERT H.5ILVEN DUNHLIJWSTEPHENSUN a-mwam Jan. 21, 1941.

H; A. SILVEN ETAL 2,229,312

FULLY AUTOMATIC CYLINDRICAL GRINDING MACHINE Original Filed June 1, 1939 5 Sheets-Sheet 4 FIE-.4

FIE-5 &

v HERBEHTHSILVEN. DEINFILDWETEF'HENEDN Jan. 21, 1941. v s v N 2,229,312

FULLY AUTOMATIC CYLINDRICAL GRiNDING MACHINE Original Filed June 1, P1939 s Sheets-Sheet 5 HERBERT Fl. 5| LVEN as I Mmm

DDNHLDWSTEPHENSU Patented Jan. 21, 1941 FULLY AUTOMATIC CYLINDRICAL GRINDING MACHINE Herbert A. Silven, Worcester, and Donald W. Stephenson, Auburn,.Mass., assignors to Norton Company, Worcester, Mass., a corporation of Massachusetts Continuation of application Serial No. 276,852, June 1, 1939. This application October 20, 1939, Serial No. 300,364

10 Claims. (Cl. 51-105) The invention relates to grinding machines, and more particularly to a full automatic grinding machine for grinding cylindrical work pieces.

One object of the invention is to provide a simshown one of various possible embodiments of the mechanical features of this invention.

Fig. 1 is a side elevation of a grinding machine embodying this invention, having a part of the ple and thoroughly practical improved full aubase broken away to show the wheel feeding tcmatic grinding machine. Another object of mechanism, and one of the work heads removed the invention is to provide a hydraulically actuto more clearly illustrate the work loading mechated full automatic grinding machine in which anism; v the various mechanisms are provided with safety Fig. 2 is a piping and electrical diagram showinterlocks. A further object of the invention is to ing the fluid pressure and electrical connections 1 provide a full automatic hydraulically operated between the various operating units and concylindrical grinding machine in which the various trol valves; hydraulic control units are electrically inter- Fig. 3 is a horizontal sectional view through locked. both of the work heads, taken approximately on Another object of the invention is to provide l e' e of 15 an automatic work loading mechanism or carrier 4 s an e d e ev o 0 an en Scale, which is provided with a plurality of work receiv- 0f the Wo k loading me having Part8 ing pockets to convey unground work pieces into bmken y and Shown in S an operative position and to convey finish ground 5 is a fragmentary horizontal Sectional k pieces from grinding position to a View, on an enlarged scale, through the work s'up- 20 charge position. A further object of the invenporemg Spindles; tion is to provide a transversely movable work 6 1S a fragmentary herlzontel sctlonal carrier which supports a movable endless chain VleW: an enlergee Scale taken apprexlmately having a plurality of work receiving pockets or on h hue 6-45 of shownfig the pm for clips thereon for conveying work pieces to and e the e earrymg chem and the Work 25 from an operative position. eleetmg mechamsm;

A further object of the invention is to provide 7 1s fragmentary horlzontal seetlonal a transversely movable work carrying apparatus vlew an enlarged.sca'le tak.en approximately having an endless chain movably supported on the 1me.1 1 of 52 showmg the gmde rod thereon with a hydraulically operated mechanism for Supmrtmganfi gwdmg the transversely to move said carrier transversely to and from an earner t operative position to grip a ground work piece 8 i ary Vertlcal .sectlonal Vlew before the work supporting centers are withdrawn an en e taken appronmatelypn the therefrom. A further object of the invention is me of Showing the gulde or guldeway to provide such a loading device with a hydraulifor ttansversely movable Work i an e di d i ch to in m Fig. 9 1s a fragmentary cross sectional view, c y 0p m e ex e me atlsm e on an enlarged scale, taken approximately on the tally advance said cha1n each time the carrier 15 line of Fig. moved forward to ground piece of W A full automatic cylindrical grinding machine Yi an unground plece Work operatlve has been illustrated in the drawings, compris- 40 position for the next grinding operation. ing a base 20 which supports a longitudinally ad- A eurther obJect P the {nveetlon 15 to provlde justable table 2! on the usual flat way 22 and V- an eJeetor meehamsm e 15 arranged e way 23. To facilitate longitudinal movement of matically to remove a finish ground Work 131868 the table 2| relative to the base 20, the table 2! from the carrier chain on each forward movei provided witha depending rack bar 24 which 45 ment of the work loading carrier. Other objects meshes t a gear 25, The gear 25 may be will be n pa v o or in part pointed out tated in a manner similar to that disclosed in the hereinafterprior United States Patent 2,117,917 to Silven The invention accordingly consists in the fead ted May 17, 1938, to which reference may be tures f construction, at s f ts. had for details of disclosure not contained herein. 50 and arrangements of parts, as will be exemplified This manual adjustment of the work supporting in the structure to be hereinafter described, and table II is merely for setting up the machine and the scope of the application of which will be inis not considered to be a part of the present indicated in the following claims. vention'. Consequently, it has not been illus- In the accompanying drawings, in which is trated in detail. 55

The base 25 also supports a transversely movable grinding wheel slide 32 which is supported on the usual v-way and flat way (not shown) to facilitate a transverse adjustment or feeding movement of the slide 32 relative to the base 20. The slide 32 supports a rotatable wheel spindle 33 which in turn supports a rotatable grinding wheel 34. The wheel spindle 33 is journalled in suitable bearings (not shown) formed within the transversely movable slide 22. The grinding Wheel spindle 33 may be rotated in any convenient manner such as, for example, an overhead drive shaft or a motor drive, such as an electric motor 35 mounted on the upper surface of the wheel slide 32. The motor 35 is provided with a multi-grooved driving pulley 36 which is arranged, by means of a multiple V-belt 31 to a multiple V-grooved pulley 38 mounted on the end of the wheel spindle 33, to rotate the grinding wheel 34 for a grinding operation,

The wheel slide 32 is arranged for a transverse feeding movement either manually for adjustment to compensate for wheel wear or in setting up the machine, or automatically during the automatic cycle of operation thereof. The wheel slide 32 is provided with a depending half nut 45 which meshes with or engages a rotatable cross feed screw 4! journalled in a slidably mounted bearing member 42 at one end and a bearing (not shown) at the other end. The forward end of the feed screw 4| is 'slidably keyed by means of a sleeve to the inner end of a rotatable shaft 43. The shaft 43 projects from the front of the machine base and is provided on its outer end with a gear 44 which meshes with a gear 45 supported on a shaft 45. A manually operable feed wheel 41 is also supported on the shaft 46 and is either formed integral with or fixedly mounted to the gear 45 so that rotation of the manually operable feed wheel 41 is transmitted through the gear 45 and the gear 44 to rotate the shaft 43 and thereby to rotate the feed screw 4| in either direction depending upon the direction of rotation of the feed wheel 41 to adjust the position of the wheel slide 32 as desired. This feed mechanism has not been illustrated in detail since it is not considered to be part of the present invention. For a more detailed disclosure of this feed mechanism, reference may be had to the U. S. patent to Silven No. 2,117,917, dated May 17, 1938 which discloses substantially the same type of feeding mechanism.

In order that the wheel slide 32 may be moved rapidly toward the work piece to grind the same automatically by the plunge-cut method, the feed screw 4| is connected through the bearing 42 with a piston rod 55. A fluid pressure cylinder 53 is arranged in axial alignment with the feedscrew 4! and contains a slidably mounted piston 54 which is connected with the piston rod 55. A fluid pressure pump 59 which is driven by an electric motor or other suitable power drive serves to pump fluid through a pipe 60 from a reservoir 5| within the base 20. The pump 59 forces fluid under pressure through a pipe 62 to a main control or feed control valve 53. The main control valve 58 is preferably of a piston type comprising a valve stem 63 and a plurality of spaced pistons which form valve chambers 64, 65 and 55 therebetween. In the position of the valve 58 (Fig. 2). fluid under pressure enters the valve chamber 65 and passes out through a passage 51 into a cylinder chamber 51 to cause the piston 54 to move rapidly toward the left (Fig. 2) to cause an infeeding movement of the wheel slide 32 and the grinding wheel 34. During the passage of fluid under pressure into the cylinder chamber 5'5, fluid is exhausted from a cylinder chamber 55, through a passage 68, into the valve chamber 65, and out through a pipe 69 which exhausts into the reservoir 6 I.

The valve stem 63 is held in a forward feeding position (Fig. 2) by means of an electric solenoid which is connected by a link 15 and a stud H to the lower end of a pivotally mounted lever 78 supported on a stud 19. The upper end of the lever 18 is connected by a pin or stud 8l'3 with a spool shaped member 8| mounted on the outer end of the valve stem 63. When the solenoid 15 is energized, the valve 53 is held in the position illustrated in Fig. 2. When the solenoid 15 is deenergized, the released compression of a spring 82 within the end of the valve casing serves to move the valve 58 quickly toward the right (Fig. 2) to reverse the position of the valve and to reverse the flow of fluid to and from the chambers 55 and 57 of the cylinder 53. The electrical apparatus for controlling the solenoid 15 will be described hereinafter.

Dash pot The piston 54 and cylinder 53 mechanism, above described, serves to cause the grinding wheel 34 rapidly to approach or recede from the work piece. In order to reduce the rapid approaching movement to a predetermined grinding feed, it is desirable to provide a wheel feed regulator or controlling mechanism, such as a dash pot mechanism, which may be rendered effective when the grinding wheel 34 is about to contact with the surface of the work piece being ground. As illustrated in Fig. 2, an outwardly projecting casing 85 is fixed to the head of the cylinder 53 and contains a pair of diametrically spaced dash pot pistons 86 and 81. The dash pot pistons 85 and 81 normally are held in a rearward position by springs 88 and 89, respectively. During the rapid approach of the grinding wheel 34, the dash pot pistons are inoperative.

The piston rod 55 extends toward the rear of the machine and is provided at its outer end with a sleeve 9| which may be adjusted longitudinally on a threaded portion 92 on the piston rod 55 and locked in adjusted postion thereon by a lock nut 93. The parts are so arranged that the sleeve 9| moves rearwardly when the piston rod 55 moves toward the rear. The dash pot pistons 86 and 81 are limited in their rearward movement by means of adjusting screws 94 and 95, respectively. When fluid under pressure is admitted to the cylinder chamber 51 to cause the grinding wheel 34 to move toward the work piece, the rapid approaching movement thereof continues until the end of the sleeve 91 engages the ends of the dash pot pistons 85 and 81, respectively. The continued movement of the piston 54 toward the left (Fig. 2) is resisted by the dash pot pistons 86 and 81, respectively, which force fluid under pressure from the dash pot chambers 91 and 98 into a reservoir 99. The dash pot chambers 9'1 and 98 are preferably interconnected with each other by the groove )2 and are arranged to exhaust fluid therefrom either through a needle valve I00 or an adjustable throttle valve [0| into the reservoir 99.

Positive stop In order to grind a Work piece to a predetermined size, it is necessary to feed the grinding wheel 3.4 toward the work piece to grind the same and then to stop the infeed and allow the grinding wheel 34 to grind out or to allow the sparks to die out in order to round up the work so that it will be ground to a true cylindrical surface of a predetermined size. As illustrated in Fig. 2, the forward movement of the piston rod 55 causes a rapid approach until the sleeve 9I picks up the dash pot pistons 86 and 8'! to cause a slow infeed which continues until an adjustable sleeve I35 engages a fixed surface I05 on the rear of the casing 85, thereby positively limiting the infeeding movement of the grinding wheel 34 and causing the wheel to dwell in contact with the work during the finish grinding period. The adjustable stop sleeve I54 surrounds the sleeve SI and is held in adjusted position thereon by means of lock nuts I06.

The throttle valve IIlI is connected by a pipe I 58 with the reservoir 99. The pipe I08 also connects the reservoir 99 toa ball check valve I59 which remains closed during the forward feeding movement of the grinding wheel but which is opened upon the rearward movement of the grinding wheel 34 as the dash pot pistons 86 and 23'! move to a rearward position to allow quick return of fluid to the dash pot chambers 51 and 98,. respectively.

The dash pot mechanism is normally an independent fluid mechanism during the normal operation of the machine. In order readily to fill the reservoir 99 to maintain the desired quantity of fluid therein, a pipe I I5 is connected between the pump 59 and reservoir 99. A valve I II is located in the pipe I III to control the flow of fluid through the pipe IIQ. An overflow pipe I i2 is connected between the vertically extending portion of the reservoir 95 and the main reservoir ti within the base of the machine so that in case the fluid within the reservoir 59 rises above a desired level, the excess fluid will return directly to the reservoir within the base of the machine. Ordinarily the valve III is merely opened when it is desired to fill the reservoir 99 and then remains closed during the normal operation of the machine. If desired, however, in order to insure the fluid level within the reservoir 59 at all times, the valve III may be opened partially so that there will be a continuous flow of fluid into the reservoir 99, and in this case the overflow pipe H2 serves to prevent the fluid level rising above the desired point.

iiorlc supporting and rotating mechanism In order to grind the entire peripheral surface of a work piece automatically, it is desirable to provide means for supporting and driving the opposite ends of the work piece tocenter and support the work piece as well as to rotate it during the grinding operation. In the construction illustrated (Figs. 3 and 5), a pair of spaced work supporting heads H5 and I55 are mounted on a swivel table IIil which is provided on the work supporting table 2|. The work heads H5 and I 95 rotatably support a pair of aligned work supporting and rotating spindles II! and II8, respectively.

The table ZI is provided with the usual swivel table H9 which is arranged to pivot on a central stud I29 set in the table 2I and projecting into a corresponding shaped aperture IZI in the swivel table H5. The upper surface of the swivel table I I9 is formed with a dovetailed surface I22. The work head I I5 is provided with a dovetailed surface I23 which mates with the surface I22 on the swivel table H5. A clamping block I24 held in position on the work head II5 by a clamping screw I25 serves securely to lock the head I I5 in position thereon. Similarly, the head I I5 is provided. with a dovetailed surface which mates with the surface on the swivel table II9, and a clamping block and clamping screw (not shown) securely clamp the work head III; in position on the swivel table II9.

The spindles Ill and H8 are provided with a suitable driving mechanism so that they may be rotated in synchronism with each other so as to provide a uniform timed driving of opposite ends of the work piece. In the construction illustrated an electric motor I34 is mounted on the left-hand end of the swivel table H9. The motor IE4 is provided with a motor shaft. I35 which is connected by a coupling I35 with a rotatable shaft I31 journalled in bearings I38 and I39 in the head II5. The shaft I31 carries at its inner end a gear IIi which meshes with a gear MI mounted on the end of a rotatable shaft I42. One end of the rotatable shaft I42 is journalled in a bearing I43 in the head I I5 and the other end of the shaft Hi2 is journalled in a bearing M4 in the head I It. The shaft M2 is connected to simultaneously rotate the spindles II? and II8, respectively. A sprocket N25 is keyed on the left-hand end of the shaft I42 (Fig. 3) and is connected with a sprocket I56 on the work spindle II! by means of a link chain H ll. An adjustably mounted idler sprocket I43 serves to take up any lost motion in the chain It? and to maintain the chain in the desired driving tension.

Similarly, the other end of the shaft I52 is provided with a sprocket I50 which is connected with a sprocket I5I mounted on the rotatable work spindle H8 by means of a link chain I52. An idler sprocket I53 serves to tension the link chain I52 as desired. By means of this driving mechanism, the work supporting and rotating spindles Ill and II8 may be rotated in synchronism with each other.

It is desirable to provide a suitable adjustment in the driving mechanism so that the two spindles having specially shaped work supporting and driving centers may be timed accurately with each other and thereafter rotated in absolute synchronisrn with each other. To accomplish this result, the sprocket I50 is not fixed to the shaft I42 but is rotatably supported thereon. A plate I55 is mounted on and fixed to a hub projecting from the sprocket I 55. The plate I55 supports a driving stud I55 which is arranged to drive a plate I5? which is fixedly fastened to the end of the drive shaft I42. The plate I5! is provided-with a cut-out portion I58 which is of sufficient size and width to allow freedom of movement and adjustment of the stud I55 carried by the plate I55. A pair of opposed adjusting screws MI and I52 which are carried by the projections I59 and IE5, respectively, on the plate I51 serve to engage opposite sides of a squared end portion of the stud I55. By slacking off on one of the screws ItI or I 52 and tightening the other screw, the plate I5I may be adjusted angularly relative to the plate III so as to time the work supporting spindle II8 in the desired relationship with the work supporting spindle Hi.

In order to clamp or look the plates I55 and I5? in adjusted position, a pair of clamping screws I55 and its are provided. These screws pass through elongated slots in the plates I5? and are screw threaded into the plate I55 so that the two plates may be. rigidly locked in adjusted position when desired, thus permitting timing of the work spindles.

Work: spindles 5 The two aligned opposed work supporting heads H5 and IIS are substantially identical in construction, the only difference being that one is a right-hand head and the other a left-hand head. Consequently, only one of these heads has been shown in detail in cross section. It should be understood, therefore, that the right-hand head (Fig. 3) is identical in construction and description with that described and illustrated in connection with the left-hand head. A collar I18 is threaded onto the end of the spindle II1 and contains a plurality of spaced symmetrically arranged springs (not shown) which are arranged automatically to apply a tension to the parts of the antifriction ball bearing I38 so that lost motion between the bearing parts is taken up at all times during the operation of the machine.

For convenience of assembly and manufacture, the spindle II1 is formed in two parts comprising the outer part I I1 and an inner sleeve correspondingly shaped aperture in the spindle I I1. The other end of the sleeve I12 is threaded and a collar I14 fitted thereon serves to lock the spindle II1 and sleeve I12 so that they rotate together. A sleeve I15 is slidably keyed within the sleeve I12 by means of a key (not shown). The outer end of the sleeve I15 is provided with a tapered aperture (Figure 5) adapted to receive the tapered portion of a work supporting and driving center I11. The center I11, as illustrated in Fig. 5, is a female center which is adapted to support and grip a partial spherical surface on the end of a work piece. A sleeve I18 within the sleeve I15 serves to support a 40 spring I19. The spring I19 is located between a flange on the sleeve I18 and a collar I80 which is screw threaded within the sleeve I12. The

compression of the spring I19 serves normally to hold the work supporting and driving center I11 and its supporting sleeve I15 toward the right (Fig. 3) into a driving position, as illustrated therein.

A fluid pressure cylinder I85 is formed either integral or fixedly mounted on the end of the work head H5. The cylinder I85 contains a piston I86 which is slidably mounted therein and is normally held in a position toward the right (Fig, 3) by two springs I81 to aid in moving and holding the work supporting center I11 in a direction toward the right to support and drive a work piece I88 having a frusto-conical surface I 88a and a partial spherical surface I882) which are simultaneously ground to a predetermined size by spaced grinding wheels 34 and 34a, respectively.

To retract the center I11, fluid under pressure may be admitted to a cylinder chamber I89 within the cylinder I85, which serves to cause the sleeve I15 to be moved toward the left (Fig. 3) against the compression of the springs I81,

The piston I86 is preferably connected with the sleeve I18 by a lost motion connection,.such as by means of a flange I98 which is provided with an integral hub that is connected to the sleeve I18 by a screw having a cylindrical end portion thereon engaging an elongated slot in the sleeve I18. The flange I8!) is positioned within a recessed portion in the left-hand end of the piston I86 and is located between the bottom of the recess I93 (Fig. 3) and a plate (not shown) which is fastened on the end of the piston I86. A collar I95 is fastened on the end of the sleeve I18 by means of a screw I88. The collar I95 is provided with an adjusting screw I91 which is arranged parallel with the sleeve I18yand which serves to adjust the amount of lost motion between the piston I86 and the flange I90. The piston I86 is arranged so that the sleeve I18 rotates therewithin and the lost motion connection between the piston and the sleeve I18 serves to allow'the spindle to be rotated and the sleeve I18 to rotate freely without any friction between the flange I88 and the piston I86. The springs I81 serve normally to hold the piston I88 in the position illustrated in Fig. 3, that is, in a position toward the right, bearing against a thrust surface which is formed at one end of the cylinder I85. This work head construction is identical with that shown in the prior U. S. patent to Silven No. 2,117,917 and consequently has not been shown in detail herein since it is not considered to be a part of the present invention. For details of disclosure not contained herein, reference may be had to the above-mentioned prior patent.

It will be readily apparent from the foregoing disclosure that the slidably mounted sleeve I15 within the work supporting spindle II1 is normally held in a position toward the right, that is, in operative position to support and drive a work piece I88 by means of the spring I19. The piston I86 is normally held in a position toward the right against the thrust surface at the end of the cylinder I by means of the springs I81.

When it is desired to retract the center after a work piece I88 has been ground, fluid under pressure is admitted to the cylinder chamber I89 to move the piston I86 toward the left against the compression of the springs I81 and to retract the sleeve I15 toward the left against the compression of the spring I19 to withdraw the work supporting and rotating center I11 to an inoperative position. The fluid pressure system for controlling the admission of fluid to the cylinder I85 will be hereinafter described.

Similarly, the right-hand head IIB (Fig. 3) is provided with a spindle and sleeve construction identical with that above described in connection with the left-hand head H5. The righthand head H6 is provided with a cylinder 280 having a piston 281 slidably mounted therein. The piston 28I is normally held in the position illustrated in Fig. 3, up against a thrust surface 282 (Fig. 3), formed at the inner end of the cylinder 288 by means of two springs 283. A lost motion connection is provided to connect the piston 28I to a sleeve 284 within the spindle II8. This lost motion connection comprises a flange 285 having a hub 285 formed integral therewith. The flange 285 is located within a recess within the end of the piston 20I and the flange 285 is located between the bottom of the recess and a plate (not shown) partially covering the end of the recess 281 (Fig. 3). The hub 288 is provided with a screw which has an inwardly projecting portion sliding within an elongated slot in the sleeve 284. A collar 2 I 0 is fixedly mounted on the end of the sleeve 284 by means of a screw 2H and is provided with an adjusting screw 2I2 arranged to engage the flange 285 and adjust the position of the flange 285 relative to the sleeve 284 and thereby adjust the amount of lost motion between the flange 285 and the piston 28 I The spindle H8 is provided with an inner longitudinally slidable sleeve similar to the sleeve I15 in the work head I i5, which in turn supports a work supporting and rotating center 214. The center 2M (Fig. 5) is preferably a hollow collet which has a center aperture to engage and support a threaded portion on the work piece I88. The spindle I it is rotatably supported by an antifriction ball bearing, similar to bearing I30 in the work head H5, and the take-up for st motion is the same. The centers I71 and 214 are shaped and arranged to grip, support and rotate the work piece to be ground.

While specially shaped centers Ill and 2M have been illustrated for supporting a partial spherical end surface and a threaded end portion, respectively, of the work piece I88, it should be understood that the shape and type of Work supporting center utilized is determined by the shape of the ends of the work piece being ground. Any suitably shaped centers may be employed to center, support, and drivingly rotate the Work piece.

Work: loading device In a machine of this type, in order to make it fully automatic in its cycle of operation, it is desirable to provide a work feeding and discharging mechanism for automatically conveying successive work pieces into alignment with the opposed work supporting and rotating centers Ill! and 234, respectively, and similarly to convey work pieces therefrom to a discharge position after a grinding operation has been completed thereon. In order to reduce the idle time of the machine during the loading and unloading operation, it is desirable to provide a work loading device whereby a continuous succession of unground work pieces are arranged in close spaced relationship with each other whereby a new unground work piece IE8 is in close proximity to the work centers when a ground work piece has been released therefrom, so that a slight movement of the loading apparatus will shift an unground work piece into alignment with the centers, thus loading and unloading the machine in a single movement of the work loading device, In the construction illustrated, a work loading device is provided comprising a transversely movable work carrier frame 228 which is slidably supported by a guide block 229 and a pair of spaced parallel slide rods 23!] and 23I (Fig. 7). The guide block 229 is of a substantially H- shaped cross-sectional area (Fig. 8). A pair of spaced parallel bars 232 which are formed as an integral part of the frame 228 engage and slide '1. in the slide surfaces of the block 229.

work carrier frame 228 serves as a sup- 102 a movable work conveyor which preferably comprises a continuous link chain 233 which is supported by a plurality of rotatable sprockets 234 and. 235 supported on studs 236 and 237, respectively, which are carried by the transversely movable Work carrier frame 228. A sprocket 238 is rotatably supported on a stud which is in turn supported by a bell crank lever Still. The upper end of the bell crank lever is pi otally connected by means of a stud 2M with the transversely movable work loader frame 228 (Fig. 4).

A sprocket 2 32 is rotatably supported on a stud 2% which is in turn carried by a vertically adjustable supporting member 24d which is adjustably supported on the frame 228. Clamping screws 255 and 2% pass through elongated slots 24'? and 248 in the vertically adjustable member 244 and are screw threaded into the transversely movable frame 228. The bell crank lever 24b is connected to a lever 250 by means of a stud 25!. The other end of the link 2% is provided with an integral threaded portion 252 which passes through an aperture formed in a boss 253 which is either formed integral wtih or fixedly mounted on a vertically adjustable member 24%. Clamping nuts 254 and 255 are provided on the threaded portion 252 and are arranged on opposite sides of the boss 253. It will be readily apparent from the foregoing disclosure that the link chain 283 passes around the four spaced rotatable sprockets 234, 235, 238 and 242, respectively, and may be readily tensioned as desired by vertically adjusting the vertically adjustable member 2% relative to the transversely movable carrier frame 228, and also by adjusting the nuts 25 i and 255 to Vary the effective length of the lever 25%.

Each of the links of the chain 233 is provided with a work receiving pocket or clip comprising a pair of spaced work supporting members 260 and 26! (Figs. 5 and 6) which are shaped to support the workpiece I88 so that when it is presented in a position between the work supporting and gripping centers Ill and 2M, the axis of the work piece I38 will be in substantial alignment with the axes of the Work supporting and rotating spindles ill and H8, respectively. As'illustrated in Fig. 5 of the drawings, the work supporting member 2% engages and supports the neck or small diameter portion of the work piece i538 and the supporting member 26! engages and supports the frusto-conical portion of the work piece as it is conveyed to and from an operating position. A pair of springs 2S2 (Figs. 4 and 6) which are arranged in spaced relationship with the members 2% and ZEI serve to hold a work piece in position on supporting members 260 and 26'! of the link chain 233. By providing a work clip or pocket on each link of the chain 233, the work pieces I88 are arranged in close relationship with each other so that only a slight movement of the chain 233 is required to index the ground piece of work away from the centers and. to present a new work piece in alignment therewith.

The work loader frame 228 is preferably moved transversely to an operating position to place a work piece in position in supporting engagement with the Work gripping centers I11 and 2M and is then moved transversely to an inoperative position during the grinding operation. This transverse movement of the work loading device is preferably hydraulically actuated by a mechanism comprising a fluid pressure cylinder 265. A pisto-n' 266 is slidably mounted Within the cylinder 265 and has a piston rod 261 formed integral therewith. The piston rod 26'! passes through a cylinder head 2% having a fluid tight packing which serves as a partial bearing support for thepiston rod Zii'l. piston rod is connected to a portion 259 of thetransversely-movable work'carrier member 228. The cylinder 255 is either formed integral with or fixedly mounted on a bracket which is fixedly supported on the work heads I I 5 and I Hi. When fluid under pressure is admitted to a cylinder chamber Till, the piston 266 is caused to move toward the right (Fig. 4) to cause a forward movement of the transversely movable work carrying device 228 so that the parts move into a broken line position with the work piece I88 assuming the position ISM so that the work piece The end of the I88 is moved into axial alignment with the work supporting centers I11 and 2I4. Similarly, when fluid under pressure is admitted to the cylinder chamber 21 I, the work carrier frame 228 is moved toward the left (Fig. 4) to move the link chain 233 and the work supporting clips into the full line position as indicated in Fig. 4.

An indexing mechanism is provided automatically to index the link chain 233 to shift an unground piece of work from an operative position after the Work centers I11 and 2I4 have withdrawn and to present an unground work piece in position in alignment with the centers for the next grinding operation. This mechanism preferably comprises an hydraulically operated indexing mechanism comprising a fluid pressure cylinder 213 having slidably mounted therein a piston 214. The piston 214 is connected to or formed integral with one end of a piston rod 215 which, as illustrated, extends in a substantially vertical direction. A sleeve 216 is supported on the lower end of the piston rod 215 and the sleeve 216 is slidably mounted within a bracket 211 (Fig. 4) which is fixedly mounted to the stationary frame of the loading apparatus. A bracket 218 is carried by the sleeve 216 and both of these members are fixed relative to the piston rod 211 by means of a pin 219. The bracket 218 serves as a support for an index finger or pin 280. The index pin or finger 288 is carried by a slidably adjustable member 28I which is arranged to be adjusted within a slot 282 (Fig. 6) formed in the bracket 218. A clamping bolt 283 passes through elongated slots 284 and 285 (Fig. 6) formed in the bracket 218 and passes through a hole within the member 28 I. A nut 286 is screw threaded onto the end of the clamping bolt 283 and serves to clamp the indexing stud or finger 288 in an operative or inoperative position. As shown in full lines in Fig. 6, when it is desired to withdraw the stud or finger 280 to an inoperative position, the nut 286 is loosened and the bracket 28I slid toward the right, the bolt 283 sliding longitudinally within the elongated slots 284 and 285 to withdraw the index finger so that it is out of the path of the work loader conveyor chain 233.

When the work loader is in an inoperative position, that is with the link chain 233 and parts in a rearmost position (Figs. 4 and 6) a stationary locating or stop stud 288- (Fig. 4) is in an operative position projecting between the spaced rollers on the link chain 233 to hold the chain against movement. When the carrier 228 moves toward an operative position so that one of the work supporting clips engages the ground piece of work I88, the link chain 233 moves from the full line position (Fig. 6) out of the path of the fixed chain locating stud 288 and the chain moves into a broken line position 233a with the link chain 233 in engagement with the index finger or pin 280. During the forward movement of the work carrying frame 228, one of the clips on the chain .is moved into position to grip the ground work piece I88, after which the work supporting centers I11 and 2H! move in an axial direction away from each other to release the ground work piece therefrom, at which time fluid is admitted to a cylinder chamber 298 at the lower end of the cylinder 213 to cause an upward movement of the piston 214 which produces an upward movement of the index pin or stud 288 to move the link chain 233 in a clockwise direction on its supporting sprockets 234, 235, 238 and 292 to present the next unground work piece into an operative position in alignment with the work centers I11 and 2M, respectively. It will be readily apparent from the foregoing disclosure that inasmuch as the work supporting clips on the link chain 233 are in close relationship with each other, only a short indexing movement of the chain is required to shift a ground work piece from alignment with the centers and to shift a new unground work piece into position with respect to said centers.

The ground work pieces are intermittently picked up by the clips on the chain and carried to a position remote from the grinding position Where they are automatically ejected or discharged by means of a discharge or ejector pawl 29I (Figs. 1 and 4) which is pivctally mounted on a stud 292 carried by the fixed frame of the loading attachment. An adjustable stop screw 293 carried by the ejector pawl 29I serves to limit the rocking movement of the ejector pawl 29I in a clockwise direction, thus locating the pawl in the desired position. A tension spring 294 serves normally to maintain the stop screw 293 in a fixed position to locate the ejector pawl 29I. When the transversely movable work carrier frame 228 is moved rearwardly, that is, toward the left (Fig. 4), after the chain 233 has been indexed, the ejector member 29I, due to its angled surface, rides up over a ground piece of work as the work moves rearwardly in a horizontal path until the ejector member 291 assumes the position illustrated in Fig. 4. On the next forward movement of the transversely movable work car rier member 228, the finish ground work piece is held by the ejector member 29I and its suppor ing clip is withdrawn therefrom and the finish ground work piece dropped into a chute or container (not shown) located below the loading device on the front of the machine base. It will be readily apparent from the foregoing disclosure that work pieces I88 are loaded into position on the chain at a position above the sprocket 234 and the work pieces are indexed intermittently as successive work pieces are ground until the finish ground work piece is ejected by the ejector member or pawl 29I.

A pair of adjustable stop screws 295 and 296 are provided to limit the movement of the index finger or pawl 299 (Figs. 1 and 4) By manipulation of the stop screw 296, the pawl 286 may be adjusted to align it with the spaces in the chain 233, and by manipulation of the adjusting screw 295 the chain 233 may be advanced a precise amount, namely one link, accurately to locate the unground work piece in alignment with the work gripping centers I11 and 2M.

The admission to and exhaust of fluid from the cylinders 265 and 213 is controlled in timed relation with the operation of the other mechanisms of the machine so that when a work piece has been ground to the required extent and the grinding wheel recedes to an inoperative position, the work carrier 228 moves forward to grip the ground piece of work. The centers I11 and 2M then withdraw to release the ground piece of work and the chain 233 is then indexed to present the next unground work piece for a grinding operation.

In the position of the parts as shown in the diagram in Fig. 2, fluid under pressure from the pump 59 passes through the pipe 62 into the chamber 55 of the valve 53 and passes out through a pipe 395, through a passage 396 in a valve 391, through a pipe 308 and a valve 389 and a pipe or passage 3H1, into the cylinder chamber 21I within the cylinder 265 to move the piston 266 together with the piston rod 261 and plate 269 carrying the work carrying head 228 toward the left (Figs. 2 and 5) to withdraw the work carrying head 251 into its rearward or inoperative position as shown. During the movement of the piston Z66 toward the left, fluid within the cylinder chamber 218 exhausts through a pipe or passage EIS and a valve chamber 3! in the valve 301 and passes through a pipe 3I5 to the valve chamber 66 in the valve 58 and through the exhaust pipe 69 into the reservoir 8!.

The valve 309 is adjusted to regulate the speed of movement of the work carrying head 228 to time it with the movement of the work centers I11 and 2M and also to reduce the force of the blow of the piston 263 at each end of the stroke to obtain smoothness and quietness of operation.

Fluid under pressure entering the cylinder chamber 21I passes through a pipe or passage 324 into a cylinder chamber 325, which serves to produce a downward movement of the piston 214 and the chain index finger or pin 289 from the position illustrated in Fig. 2 into the position illustrated in Fig. 4. During the downward movement of the piston 214, fluid is exhausted from a cylinder chamber 290, through a pipe or passage 321, in a manner to be hereinafter described.

The valve 391 is normally inoperative and remains in the position illustrated in full lines in Fig. 2, except when it is desired to set up the work carrying frame 228 and its associated mechanism when the same may be manually operated to move the work carrying frame 228 independent of the other mechanisms of the machine.

When the wheel feed control valve 53 is shifted into its reverse position, the direction of flow of fluid under pressure to the cylinder 265 is changed so that fluid under pressure passes through a pipe 313 into the cylinder chamber 218 to cause the piston 266 to move toward the right (Figs. 2 and 4) so as to move the work carrying frame 228 into an operative position.

Electrical control and. interlock In a machine of this type, it is desirable to provide suitable interlocks between the various mechanisms of the machine to insure safe operation thereof, without endangering the operator or damaging the work pieces I88 passing therethrough. It is desirable to provide an electrical interlock between the work gripping centers I11 and 2|4 and the wheel feed control valve 58 so that the solenoid 15 cannot be energized unless both of the work gripping centers are in an operative position in engagement with the work piece I88 to be ground. The mechanisms of the machine, as shown diagrammatically in Fig. 2, are in a grinding position. A trip switch 336 is normally held in a closed position by means of a spring 331. An actuating plunger 338 is arranged in the path of an adjustable screw 333 carried by a pivotally mounted lever 348 mounted on a stud 34I fixed to the end of the cylinder I85 of the work head II5. A rod 342 is fixed to the piston I86 and projects through an aperture within the end cover of the cylinder I85 and is arranged to engage the lever 348. A spring 343 having one of its ends connected to the upper end of the lever 349 and its other end connected to a stud 344 fixed to the top of the cylinder I35 serves normally to maintain the lever 33% in engagement with the rod 342. In the position of the parts shown, Fig. 2, the switch 336 is closed. When fluid under pressure is admitted to the cylinder chamber I89 to cause the piston I86 to move toward the left to withdraw the work centers I11 and M4 to an inoperative position, the rod 342 rocks the lever 340 in a counterclockwise direction, which serves to move the switch actuating plunger 338 toward the left, Fig. 2, to trip the switch 336 and thereby break the circuit.

A similar safety connection including a normally closed trip switch 345 is normally held in a closed position by means of a spring 346. An actuating plunger 341 is arranged in the path of an adjustable screw 348 carried by a pivotally mounted lever 349 mounted on a stud 359 fixed to the end of the cylinder 288 of the work head HE. A rod 35I is fixed to the piston 2I1l and projects through an aperture within the end cover of the cylinder 268 and is arranged to engage the lever 349. A spring 352 having one of its ends connected to the upper end of the lever 349 and its other end connected to a stud 353 serves normally to maintain the lever 349 in engagement with the rod 35L In the position of the parts shown in Fig. 2, the switch 345 is closed. When fluid under pressure is admitted to the cylinder chamber 2I2 to cause the piston 29! to move toward the right (Fig. 2) to withdraw the work center 2I4 to an inoperative position, the rod 35I rocks the lever 349 in a clockwise direction which serves to move the switch actuating plunger 341 toward the right (Fig. 2) to trip the switch 345 and thereby break the circuit.

A similar trip switch 339 is operatively connected to be actuated by a cycle timing valve to be hereinafter described. The switch 360 is normally held in an open position by means of a spring 36I and is provided with an actuating plunger 362 which is arranged in the path of an adjustable screw 363 which is mounted in the upper end of a rock arm 364. is pivotally mounted on a stud 365. The lower end of the rock arm 364 is arranged to engage a plunger 366 which extends from and is formed integral with a piston 361 of a cycle timing cylinder 368.

Cycle timing piston and cylinder The cycle timing piston 351 and cylinder 368 serve to control the admission of fluid under pressure to the work head actuating cylinders I85 and 288 in timed relation with the other mechanisms of the machine. The piston 361 is normally held in a right-hand position (Fig. 2) by means of a pair of springs 369 and 310 which are connected between studs 31I and 312, respectively, n the cylinder casing, and the other ends of which are fastened to studs 313 and 314 on the rock arm 354. to rock the rock arm 364 in a counterclockwise direction. A cylinder chamber 315 within the cylinder 338 is connected by a pipe 316 with a passage 311 in a cycle timing valve 318. The passage 311 is connected by a ball check valve 319 with a passage 386 which enters a valve chamber 39E within the piston type cycle timing valve 318.

The pipe 316 leading from the cycle timing piston and cylinder 368 also connects with a pipe 382 which in turn is connected with an exhaust pipe 383 to exhaust fluid into the reservoir A valve 384 is located in the pipe line 382 and serves to close oil the exhaust from the cycle timing valve when desired in setting up the machine for grinding a given Work piece I88. An adjustable throttle valve 385 is also located in The rock arm 364' These springs normally tend the pipe line 382 and serves to adjust and control the rate of exhaust from the cycle timing piston and cylinder 388 and thereby to control the cycle of operation. When the fluid is exhausted from the chamber 315 in the cycle timing piston and cylinder 368 by the piston 381, the ball check valve 319 is closed by back pres sure of the fluid so as to allow fluid to exhaust only through the pipe 318 to the needle valve 385 in the pipe line 382 to exhaust through the pipe 383.

Cycle timing valve The cycle timing valve 318 is preferably a piston type valve comprising the valve pistons 388, 381 and 388 which are formed integral with a valve stem 389, thus forming valve chambers 398, 39I, 392 and 393.

As shown in Fig. 2, fluid under pressure from the pump 59 passes through the pipe 82 and through a pipe 394 which connects with the valve 318. In the position of the parts as shown, the valve piston 386. closes the port for the pipe 398. Fluid under pressure passing into the control valve 58 passes out through a pipe 385 and through a pipe 395 and a throttle valve 395 into the valve chamber 390 to move the cycle timing valve to the right-hand position, as shown in Fig. 2. The valve 3% serves to control the rate of admission of fluid to the valve chamber 398 and thereby controls the rate of movement of the cycle timing valve. During this movement of the cycle timing valve, fluid within the chamber 393 exhausts through a pipe 391, an adjustable throttle valve 398 and a pipe 3I5, which exhausts fluid through the valve chamber 88 and returns it through the pipe 69 to the reservoir BI. The valves 396 and 398 serve to control the rate of movement of the cycle pilot valve.

When the main control valve 58 is reversed and fluid under pressure is admitted to the pilot valve chamber 393 to shift the pilot valve 313 toward the left, fluid under pressure passing through the pipe 394 may enter the valve chamber 39I and pass through the passage 380, the ball check valve 319, the passage 311, the pipe 316, into the cycle timing piston and cylinder 368 to cause the piston 381 to move toward the left, thereby rocking the rock arm 384 so that the released compression of the spring moves the switch plunger 382 toward the right (Fig. 2) which in turn closes the switch 389. At the same time, the released compression of the springs serves to move the pistons I88 and 29I simultaneously toward each other so that the work spindles grip the next work piece, thereby closing trip switches 336 and 345, which closes the circuit and serves to energize the solenoid 15 to shift the control valve 58 so as to start the infeeding movement of the grinding wheel.

An adjustable stop screw 488 on the cycle timing cylinder 388 serves to limit the movement of the piston 381 toward the left and thereby permits adjustment of the capacity of the cycle timing piston and cylinder so as to admit the desired amount of fluid to obtain the cycle of operation desired.

A push button ADI is provided in the electrical circuit to stop and start the cycle of operation. This switch MI is connected in series with the normally closed trip switches 336, 345 and the normally open trip switch 368.

Operation.

The operation of this machine is readily apparent from the foregoing disclosure. When it is desired to start the machine in operation, a control button on the front of the machine base is actuated to start the wheel rotation, a push button is actuated to start the fluid pump, and a push button is actuated to start the work drive motor I33. The push button switch 48I is then actuated to start the cycle of operation. The switch MI is connected in series with the trip switches 335, 345 and 350 and serves to energize the solenoid 15 which shifts the control valve 58 into the position shown in Fig. 2 to start a forward feeding movement of the grinding wheel 34. Assuming a work piece to be already located on the work centers, fluid under pressure entering the valve chamber 65 passes into the cycle pilot valve chamber 390 to shift the cycle pilot valve 318 into the position illustrated in Fig. 2. The grinding wheel 34 advances to grind the work I88 to the required size and the extent of the grinding operation, that is, infeed and dwell, is determined by the adjustment of the cycle timing piston and cylinder 388 which meters fluid from the valve chamber 315 through the variable throttle valve 385 into the exhaust. When the cycle timing piston 391 has moved toward the right a sufficient distance during the grinding operation, the trip switch 388 is opened, thereby breaking the circuit and deenergizing the solenoid 15 which releases the compression of the spring 82 and returns the feed control valve 58 to its reverse position so that fluid under pressure is admitted through the valve chamber 65 into the cylinder chamber 56 to cause a rearward movement of the grinding wheel 34. The shifting of the feed control valve 58 admits fluid under pressure through the pipe 3I5 and the pipe 391 into cycle pilot valve chamber 393 to start the cycle pilot valve 318 moving toward the left and at the same time passes fluid through the passage 3I4 in valve 301 and through the pipe 3I3 into the cylinder chamber 210 to move the work carrying member 228 forward simultaneous- 1y to grip the ground piece of work I88.

When fluid is admitted through the pipe 391 into the pilot valve chamber 393 to cause the cycle pilot valve 318 to move toward the left, fluid is also admitted from the pipe 391 into the pilot valve chamber 392 and passes out through a pipe M9 which passes fluid through a passage M I in a valve H2. Fluid entering the valve chamber M I passes through a pipe 4 I3 and a pipe 4M into the cylinder chamber I89 of the cylinder I85 and also passes through a pipe 4I5 into the cylinder chamber 2 I2 of the cylinder 288 to cause the work grip-ping centers I 11 and 2M simultaneously to move away from each other out of gripping engagement with the work piece I88. Fluid under pressure is admitted to the cylinder chambers I89 and 2I2 only instantaneously while the timing.

valve 318 is being moved toward the left.

The speed of movement of the cycle pilot valve 318 as governed by the valves 396 and 398 is such as to allow time for the work centers I11 and 2 I4 to be disengaged from the work piece I 88, and the Work carrier chain 233 to be indexed to remove the finished work piece I88 and present an unground work piece I88a into alignment with the work centers I11 and 2I4 before the valve piston 388 covers the port to cut off fluid from the pipe M0.

During the period while the work gripping centersare separated, a pipe M6 is uncovered by movement of the piston I86 toward the left (Fig. 2) which serves to admit fluid under pressure through a valve M1 and pipe or passage unground work piece with'many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as --many changes might be made in the embodiment above set forth,-it is to be understood that all matter hereinbefore set forth or' till-into cylinder chamber ZQO-t'o move the piston 214 upwardly, thereby to shift the ground piece of work I88 into a discharge position I88 and simultaneously to move a new piece of work [88a into axial alignment with the work gripping centers. The arrangement above described is such that the passage'of fluid into the cylinder chamber 2% through the valve 4!! is controlled in timed relation with movement of the pistons I86 and 20! which actuate the work gripping and rotating spindles.

When fluid under pressure is cut oil from the pipe "M0, the released compression of the springs I81 and 203, the spring H9 in the work supporting head H5, and a similar spring in the work head l [6 serve rapidly to move the work spindles simultaneously toward each other to engage the work centers Ml and'ZM with the [88s. This movement serves rapidly to exhaust fluid from the work spindle cylinder chambers 189 and 212 in the cylinders H35 and 200. Any leakage of fluid by the pistons I85 'and 2fll is-exhaustedby an eX- tension of the pipe 383 into the'reservoir Bl The movement ofthe work spindles into an operative so as to move the grinding wheel 35 toward the valve 391, through the pipe 3%, the valve 3li9 and thepipe 3H1, into a cylinder chamber 2',

to move the work carrier frame 228 to an inoperative position, as shown in full linein Fig. 4. The radially extending holes 32 are uncovered when the piston "226 reaches its l-eft-handposition (Figs.'2 and 4), and fluid passes from the cylinder chamber 2H through the pipe or passage 324 to the cylinder chamber 325 to move the piston 27 i and index pin 285) downwardly into the position shown in Fig. 4. During the downward movement of the-piston 274, fluid is exhausted from the cylinder chamber 2% through the pipe H6, a ball check valve in cylinder I85, andthrough the-pipe' ll l, the pipe 413, the valve M2, the pipe M and the pipe M9, into the reservoir 6|.

The valve M2 is provided to facilitate independent movement of the work supporting centers [11 and2l4 in setting up and adjusting If it is desired manually to-operate the pistons 185 and 29! independent of the cycle control mechanism, the valve-M2 is shifted in a clockwise position into the position illustrated in dotted lines in Fig. 2 so that fluid under pressure from the pump 59 is admitted to the cylinder chambers A89 and 2|2, respectively, to withdraw the work supporting centers independently of the cycle control.

This cycle of operation is then continued on successiv'epieces of work. 'By manipulation of the various control valves,'the timing of the movement of the various hydraulically actuated parts may be regulated as desired to obtain the desired coordination in the movement of the various parts of the machine.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together shown in the accompanying drawings is to be interpreted as-illustrative and not in'a limiting sense.

This applicationis aco'ntinuation of "our copending application Serial No. 276,852 filed June 1, 1939.

We claim:

- 1. In an automatic cylindrical grinding ma Chine having a p of ppo ed aligned 'work rality-of spaced work receiving pockets, an end-" less chain to support said pockets on said head, means to move said head transversely to grip awork piece supported on said spindles, an indexing mechanism including a piston and cylinder to index said movable support relative to said head'simultaneously to transfer said work pieces,

and connections between one of said spindles and said endless chain indexing mechanism whereby said second cylinder is rendered inoperative untiljsaid spindles havemoved'to an' inoperative position.

2. In an automatic cylindrical grinding machine having a pair of opposed aligned work supporting and rotating spindles, 'means synchronously to rotate said spindles, means including; a piston and cylinder tomove each of said spindles toward and from each other, and a work loadingdevicehaving a transversely movable work carrier head, a. piston and cylinder to move said head transversely, a movable endless chain sup-Ii. portedon said'carrier head, a plurality of spaced work receiving pockets on said chain, means including a piston and cylinder to index said chain so as to shift the work pieces intermittently into alignment with said spindles and into a dis-t charge'positioma control valve to admit fluid to said first cylinder to move'the work carrier head transversely, a cycle timing valve actuated by said'main control valve, connections between said cycle timing valve and said spindle actuat ing cylinders to control the movement of said spindles in timed relation with the movement of said work head, and fluid pressure connections between one of said spindles and said endless chain actuating cylinder which are arranged tot; render the indexing cylinder inoperative until the work spindles have separated and moved to an inoperative position.

3. In an automatic cylindrical grinding machine having a pair of aligned work supporting and rotating spindles, means including a fluid pressure pistdn-aridf'cylinder operatively connected .tojniove said spindles toward and from each other,'a work loading mechanism comprisincluding a piston and cylinder to index said chain so as to remove the ground piece of work and to present a new piece of work into axi-al aligmnent with the Work supporting spindles, and

ya hydraulic interlock between said spindle actuating cylinders and said endless chain operated cylinder whereby said latter cylinder is rendered inoperative until the work spindles have separated to release a ground piece of work.

4. In an automatic cylindrical grinding machine, a work loading device having a transversely movable work carrier, a plurality of sprockets rotatably supported thereon, an endless chain supported by said sprockets, a plurality of work receiving clips on said chain, a fluid pressure piston and cylinder operatively connected to move the carrier transversely to and from an operative position, an index pin engageable with said chain when said carrier is moved in one direction, and means including a second piston and cylinder to traverse said pin to index said chain successively to present a plurality of work pieces for a grinding operation.

5. In an automatic cylindrical grinding machine, a work loading device having a transversely movable work carrier head, a plurality of sprockets rotatably supported thereon, an endless chain supported by said sprockets, a plural- 'ity of work receiving clips on said chain, a fluid pressure piston and cylinder to move said carrier transversely to and from an operative position, an indexing mechanism including a movable index pin engageable with said chain when the work carrier is moved forward, and means including a second piston and cylinder to traverse said index pin to index said chain and present the next Work piece in operative position.

6. In an automatic cylindrical grinding machine, a work loading device having a transversely movable work conveyor, a plurality of sprockets rotatably supported thereon, an endless chain supported by said sprockets, a plurality of work receiving clips on said chain, a fluid pressure piston and cylinder to move said carrier transversely to and from an operative position, an index pin engageable with said chain when the work carrier is moved in one direction, means including a second piston and cylinder to transverse said index pin to index said chain to present successive work pieces for a grinding operation, and an ejector member on said work loading device which is arranged positively to eject a ground work piece from a clip on said chain when the carrier moves transversely toward an operative position.

7. In an automatic cylindrical grinding machine, a Work loading device having a transversely movable work carrier head, a plurality of sprockets rotatably supported thereon, an endless chain supported by said sprockets, a plurality of work receiving clips on said chain, a fluid pressure piston and cylinder to move said carrier transversely to and from an operative position, means including a second piston and cylinder to index said chain successively to present a plurality of work pieces for a grinding operation, and means including an adjustable stop to limit 4 the movement of said second piston so-as to adpiece of work supported on said spindles, means just the extent of said indexing movement so as to align the work piece in an operative grinding position.

8. In an automatic cylindrical grinding machine, a work loading device having a frame fixedly mounted on said grinding machine, a transversely movable work carrier head supported on said frame, a plurality of rotatable sprockets supported on said carrier, an endless chain supported on said sprockets, at least one of said sprockets being adjustable relative to the others to tension said chain, a plurality of work receiving clips on said chain, means including a fluid pressure piston and cylinder to move said carrier transversely to and from an operative position, and an indexing mechanism including a movable indexing pin and a fluid pressure piston and cylinder operatively connected to traverse said pin to index said chain so as to successively present a plurality of work pieces for a grinding operation.

9. In an automatic cylindrical grinding machine, a work loading device having a frame fixedly mounted on said grinding machine, a transversely movable work carrier supported on said frame, a plurality of rotatable sprockets supported on said carrier, an endless chain supported on said sprockets, at least one of said sprockets being adjustable relative to the others to tension said chain, a plurality of work receiving clips on said chain, means including a fluid pressure piston and cylinder to move said carrier transversely to and from an operative position, an indexing mechanism including a movable indexing pin and a fluid pressure piston and cylinder operatively connected to trav erse said pin to index said chain so as to successively present a plurality of work pieces for a grinding operation, and an ejector member on said frame which is arranged to eject a ground work piece from a clip on said chain when said carrier moves transversely toward an operative position.

10. In an automatic cylindrical grinding machine, a work loading device having a frame fixedly mounted on said grinding machine, a transversely movable work carrier supported on said frame, a plurality of rotatable sprockets supported on said carrier, an endless chain supported on said sprockets, at least one of said sprockets being adjustable relative to the others to tension said chain, a plurality of Work receiving clips on said chain, means including a fluid pressure piston and cylinder to move said carrier transversely to and from an operative position, an indexing mechanism including a movable iii-- dexing pin and a fluid pressure piston and cylinder operatively connected to traverse said pin to index said chain so as to successively present a plurality of work pieces for a grinding operation, and a pivotally mounted ejector member on said frame which is arranged to engage a ground work piece when the carrier moves to an inoperative position and to eject said work piece when said carrier moves toward an operative position.

HERBERT A. SILVEN. DONALD W. STEPHENSON.

CERTIFICATE OF CORRECTION. Patent Nor 2,229,512. January 19 n HERBERT SILK/EN; ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requjr ing correction as follows: Page '10, first column, line 149-50, claim 6, for the word "transverse" read travers and that the said Letters Patent should be read with'this correction therein that the same may conform to the record of the case in the Patent Office..

Sign and sealed this 15th dayof May, A. D. l9) |.1.

' Henry Van Arsdale', (Seal) Acting Commissioner of Patents. 

